Saturday, November 28, 2009

The next form of "the Rosettifolias" is perhaps the most ornate of them all. The foliage on P. rosettifolia #3 is very showy indeed. It is often a winner at shows when out of bloom due to the light yellow veination along the central and lateral veins of the deep almost black-green leaves.Petrocosmea rosettifolia #3 is also sometimes labeled P. sp. 'G25KC00'. It was brought into cultivation around the year 2000, after being imported from Chen Yi Nursery (or Kaichen Nursery) in China as a wild collected plant. This form produces the largest rosette of any of the forms. Leaves are more elliptical in shape, forming a sharp point, with teethed or serrate margins. The leaf is very deep glossy green, almost black in the right light. The centers show a bright yellow veination along the central and lateral veins. Leaves are covered in a course hair and have a rough texture. The rosette tends to be very symmetrical naturally. This form does produce offsets quite readily as it approaches flowering, which unfortunately, often ruins the flat rosette. Flowers are produce singly, on stout light green peduncles, with three bracts. Flowers on this form are clear, bright white, with a yellow throat, and often have four or five lower petals.

The clear white flowers of P. rosettifolia #3 have a lemon yellow center and usually extra petals. Note how the two upper petals are fused into a green hood on the top of the flower. These petals, if measured from base to tip are about one half the length of the lower petals...a characteristic which places this species within Section Anisochilus of the genus Petrocosmea.

My show plant of P. rosettifolia #3 entered in the July 2009 annual convention show of the Gesneriad Society in Silver Spring, MD. The plant won both a first place in it's class and Best Petrocosmea in the show....likely due to the extra ornamental value added by the yellow center veining of the glossy leaves. The contrast is quite showy. The plant was seven inches in diameter.

This photo shows the peduncles on P. rosettifolia #3 which have three bracts, instead of the two bracts found on forms #1 and #2. This form's flowers also have extra lower petals. This photo also shows the rough texture to the glossy leaves and the teeth along the leaf's margins. (The white tag is marking the parentage of a seedpod on the peduncle on the left.) The more compact rosette of P. rosettifolia #2 is in the background. Note that it does not reach the margins of the 5" pot, while the leaves on the larger rosette of #3 are extending over the pot's edge.

A favorite shot of the center of the rosette of P. rosettifolia #3, shows the nice yellow veination forming a yellow feather pattern in the center of the leaves. Even without flowers, this form is a showy plant.

When I first began to assemble a collection of every known Petrocosmea species in cultivation, about five years ago, I noticed that I had two different plant labeled as Petrocosmea rosettifolia. They looked different in several ways. Then as time went on, I began to notice that some of the P. rosettifolias entered in shows were different from the two plants I had. I decided to get leaves of all the various forms I could find and conduct an experiment. I put leaves of all four forms that I had collected down to root on the same day. I treated them identically in every way. When they had formed plantlets, I divided and potted up the plantlets on the same day, using the same soil, pots, fertilizer, etc. I grew them on the same shelf of my lightstand. The culture was identical in every way, at least as much as I could make it so. As these four individuals matured, I could easily see the differences. I decided to label them P. rosettifolia #1, #2, #3, and #4 so that I could keep them seperately identified and kept records of each form. Were they different species, or just different clones of the same species, perhaps from different collections or populations in nature? Those questions are still being answered, but with time, based on morphology and now some new DNA analysis, I am convinced that they are indeed four unique individuals within the same species. I do, however, have real doubts that they are indeed the true P. rosettifolia, but I am leaving them labeled as such for the timebeing. I feel that it is important to both Petrocosmea admirers as well as AV and gesneriad judges and exhibitors to know that there are four different clones of this species in cultivation and they grow and perform differently. Furthermore, I believe that the plants now being grown as P. menglianensis and P. sp. 'China 2005' may also be two additional clones of this same species, based on the DNA analysis which is being done as well as morphological characteristics of these plants. Two others, P. sp. 'Chinese #2' and P. sp. 'Yumebutai' is also very closely related to this group and may be two additional forms of the same species. I refer to all of these collectively as the "Rosettifolia group". I decided to review the four forms that I have identified here.The first is of course, P. rosettifolia #1. My plant was labeled as coming from the collection of the late Maryjane Evans, and it is believed to have been a plant collected in China around 1998-2000. This form is the smallest of the four clones in plant size. It has never reached the edges of the 5 inch pan pot in which I have grown it for the past three years. It's rosette is rather tight, and leaves are the smallest of the four clones, and are nearly plain dark green, with only a slight gloss to them. The yellow center vein coloration so prominent in the leaves of some other forms of this species, is very faint in the leaves of this form. Leaf margins are entire, or smooth, showing no teeth as some forms do. The flowers of this form are produced on single-flowered peduncles, with two bracts, which tend to be the shortest peduncles of the four forms and the most often curve gracefully at the tip, causing the open flowers to "nod" downward slightly. The flower form shows two fused upper petals forming an hooded lip, which is green in color and only half the length of the lower three petals, which are a pinkish lavender in color. It forms a rather charming little rosette when in flower. It is a favorite of mine for it's simple charm.

The flowers of P. rosettifolia #1 are the closest to pink of any Petrocosmea species in my collection. The subtle coloration of pink, lavender, white, creamy yellow and green is lovely.

The next is P. rosettifolia #2. The origin of this plant is unclear, but it was believed to have been brought into cultivation via a purchase from Chen Yi Nursery, in China. My plant was purchased from a commercial vendor here in the USA four years ago. This plant is very similar to #1, but grows a bit larger in all it's parts. Leaves are larger and the rosette just reaches 5 inches in diameter. Leaves are a bit glossier than #1, and the rosette is slightly more open in form. Flowers are nearly twice the size of the flowers on P. rosettifolia #1. The peduncles are single flowered, with two bracts and are very straight, with little or no curvature at the apex once the flower buds open. Flowers are presented facing outward and upward. Coloration on these is more lavendar, with little to no pink coloration. Flower form is identical to form #1 and very similar to P. menglianensis. This form appears identical in all respects to the plants now being grown here in the USA as P. sp. 'Chinese #2'.

A blooming plant of P. rosettifolia #2. A bit larger than form #1, again without the yellow central veining that some forms show. Leaf margins are entire, showing no teeth. This form bear two bracts on each peduncle.

The flowers of P. rosettifolia #2 are twice the size of those on P. rosettifolia #1.

This photo shows P. rosettifolia #1 on the lower left, with P. rosettifolia #3 above. You can just see the leaves of P. menglianensis to the right of P. rosettifolia #1.. Note the difference in the rosettes of each species, along wit the leaf margins and the yellow veination of the leaves on #3. I believe P. menglianensis to be the same species as the rosettifolias. It's leaves are quite large, and show the yellow veination that form #3 does, but have a smooth or entire margin, whereas form #3 had a serrate leaf margin and a narrower, more pointed leaf shape.

By growing the various forms side by side, it becomes easy to note the similarities and differences in the plants. The photo above shows how they were grown on the lightstand. Note the white acrylic blanket matting in the bottom of the nursery tray, which is used to maintain higher humidity around the plants.

A couple of additional points I'd like to make about the various forms of P. rosettifolia. Forms #1 and #2 have smaller habits, which judges should take into account when judging these species. The leaves are less ornate, having plain green coloration. The leaf margins are smooth, or entire on the forms #1 and #2 and are serrated, with teeth on forms #3 and #4 which will be discussed in the next post. The peduncles of forms #1 and #2 consistently have two bracts, while those of forms #3 and #4 consistently have three bracts per peduncle. Last, I would like to state again, that these plants are labeled P. rosettifolia, but I believe they are NOT the true P. rosettifolia as described in the Flora of China. I believe they may indeed be an undescribed species. DNA evidence being finalized now, shows that the four forms of P. rosettifolia that I am describing here are very closely related, so closely that they are likely all the same species.

Thursday, November 12, 2009

I've posted previously about the maddening problem with Petrocosmea species having been introduced under erroneous names. This misidentification or mislabeling, or whatever we choose to call it is a mess now to sort out. I'm excited that there may be some hope towards correcting at least some of the names in the near future. I've written and spoken for some time now about the particular problem with those plants currently labeled as P. "rosettifolia" and/or P. sp. 'G25KC00'. (Honestly, in my opinion, the label 'G25KC00' is probably the most responsible labeling we could apply to this group of plants right now.) Over time, I have collected at least four different individuals (clones) with these labels. These plants all show similar, but individual characteristics. In my opinion, after growing them all side by side, and conducting a little research of my own, I feel they are all seperate individuals of the same species. Now, I have yet another plant that I would like to add to this grouping - Petrocosmea "menglianensis".

A young, flowering plant that I acquired as P. "menglingensis" (there is no such species with that spelling, I feel it was supposed to have been labeled P. menglianensis (the published spelling of a species). I now feel this plant is NOT P. menglianensis either, but another clone of the grouping currently knows as P. "rosettifolia".

The flower of P. "menglianensis" is almost identical to the flowers of the four individuals that I have acquired as P. "rosettifolia". The flower on this plant is a bit more lavender in color, but morphologically is identical to P. "rosettifolia" flowers.

A side view of a flower of P. menglianensis shows the upper lip, which is the fused upper two petals. The upper lip of the flower is roughly one-half the length of the lower petals, a trait that likely puts this species in Section - Anisochilus of the genus Petrocosmea.

A flowering plant of P. "rosettifolia" #2, the plant is almost identical to the plant labeled P. "menglingensis" when I acquired the former. The plants have near identical flowers and the leaves are identical except that the leaves of the plant labeled P. "menglingensis" are nearly twice the size of the leaves of P. "rosettifolia" #2. I feel they are two seperate clones of the same species.

A flower of P. "rosettifolia" #1, again, nearly identical to the flowers of P. "menglianensis". This form of "rosettifolia" is the smallest of the now five forms of the species that I have. The cymes on this form are darker purple in color, shorter, and tend to curve, causing the flowers to "nod".

I realize this is all very confusing. Here's the breakdown of what I am attempting to say here:

#1 There are at least four different individuals of the same species all labeled as P. "rosettifolia". I feel that this new plant, which I acquired as P. "menglingensis" is yet another form of the same species.

#2 All four (now five) plants in this grouping all likely NOT the true P. rosettifolia. None of them match the published description of that species in the Flora of China.

#3 The plant which is the subject of this post originally came to me, and is still being sold and distributed as P. "menglingensis"...which is an erroneous spelling of P. menglianensis (the published species name). I feel that this plant is NOT P. menglianensis, and is yet another different clone of the plants all now being grown as P. rosettifolia. It is NOT P. rosettifolia either, but is almost identical to all of the other plants being grown under the erroneous labeling of P. rosettifolia.

#4 If my hunch is true, there are now at least five different individual clones of this same species, which is not yet properly identified.

#5 If you have this plant, I would recommend continuing to keep it labeled as it is, in order to identify it seperately from the other "P. rosettifolia" clones....BUT with the knowledge that it is likely not either P. menglianensis OR P. rosettifolia....we simply don't have a proper identification on any of these plants at present.

WHEW!!! I hope this is all as clear as mud, at least. Either way, the plant is still lovely, and a welcome addition to the genus in my plantroom. It does grow much larger than any of the other forms of the species (whatever species that is?) and should be grown in for no other reason than to preserve it's genetics. The leaves on this form get quite large on a mature plant and with maturity, in it's third of fourth year, it can bloom quite heavily.

Wednesday, November 11, 2009

Sometimes, one of the toughest things about hybridizing gesneriads is selecting a name for the hybrids. (the second toughest thing is the selection process where most of the seedlings to flower must be thrown into the garbage bin!) I was surprised a couple of years ago, while looking at a batch of hybrid Petrocosmea seedlings to note that one of them had leaves that were yellow...definately more yellow or golden than all of it's siblings. My first thought was that the plant was just chlorotic, so I repotted it and gave it a heatlthy dose of fertilizer. It only became more yellow! As the plant matured, I had removed some of the leaves to test whether the propagations from the leaf cutting would show the same trait. They do! This seedling was eventually selected due to the unique trait of the golden yellow overlay of color on the leaves. I noted that various exposures to light produced slightly different degrees of intensity in the yellow coloration, but this plant always remained more yellow than all the other Pets. I suspect that it's parent, P. rosettifolia #3 which was used due to it's deep yellow veining in the leaves is the contributor to this trait. The flowers, being light lavendar, make a lovely color contrast to the yellow foliage. So, what to name it? The yellow color appears to be overlaid upon the green leaves underneath, like the glow of a full moon upon an object, so I was inspired to name the plant 'Keystone's Harvest Moon'. The cross is P. rosettifolia #3 x sericea.

A young blooming plant of P. 'Keystone's Harvest Moon'. While the flowers are produced on long pedicels, a trait I normally wound have culled out in a seedling, the yellow pigmentation of the leaves promises the beginning of some interesting foliar characteristics if I can get the plant to hybridize. One of my goals for hybridizing Petrocosmea is to introduce new, more ornamental foliage, since often Pets are entered in shows as "non-flowering" entries.

A close up shot showing the lavendar flowers of P. 'Keystone's Harvest Moon'. This color makes a lovely contrast with the yellow foliage which can be seen in the background.

A photo showing P. 'Keystone's Harvest Moon' on the right, beside a young plant of P. menglienensis, to show the yellow foliage color of 'Keystone's Harvest Moon'. The plant is NOT chlorotic. I have tested it with a number of leaf propagated plants and all show the yellow leaf color even in various conditions. Light intensity tends to affect the degree of yellow coloration, with higher light producing the most intense yellow coloring.

Thursday, November 5, 2009

A flowering plant of Petrocosmea minor veined leaf form. This form grows larger than any of the other forms, with heavier substance. Leaves and even flower petals show deeply incised veining along the central veins, lateral veins and even in between the lateral veins.

A close up photo the foliage of P. minor veined leaf form. Very glossy and bubbly in appearance, making quite an attractive plant in or out of flower. This form also seems to propagate the most quickly and readily from leaf cuttings and has the fastest growth rate of all the forms.

A close-up shot of the flower of P. minor veined leaf form, shows the recurved petals with the deep veining of the lower petals. Cymes are single to multiple flowered, with more branching of cymes on more mature plants. Cymes of this form have a sturydy, heavy substance.

The third form of P. minor in cultivation is the form now called P. minor veined leaf form. This form has been distributed as P. sp. '#5', P. sp. 'Chinese #5', and simply P. minor. It differs from the other forms most obviously in the deep veining of the large, heavy, glossy orbicular leaves. The petiole often has dense, quite long silvery hairs covering it, with these hairs being golden amber to brown near the base of the petiole. This form did succeed in a cross with P. sericea, using sericea as the pod parent. Seedlings of the cross can be seen in an earlier post on here a few days ago. The leaves of the seedlings do show the influence of P. minor veined leaf form, as they are all deeply veined even as small plants.

As new Petrocosmea species are collected and brought into cultivation, additional forms of P. minor are showing up. The plant pictured above was just collected and imported from China in late 2008 and appears to be another clone of, or at least very closely related to P. minor. I have small seedlings of this new form in my collection and am anxiously awaiting first flowers.

I hope that this discussion of the various forms of Petrocosmea minor is informative and helpful to enthusiasts and judges. Further study of these plants are causing me to be more and more certain that all of these plants are NOT truly P. minor. They differ from the published description in many significant ways. I feel more and more that these represent an undescribed species or "new" species to cultivation. Until this is confirmed, however, I recommend that plants be grown and labeled as we describe them here. Retaining the source of your plants is important. I try to keep records of the original labeling and source of all of my Petrocosmeas in the hopes that soon a taxonomist will provide come clarity to the labeling of these spectacular gesneriads.

Monday, November 2, 2009

A flowering plant of Petrocosmea minor pointed leaf form shows the smaller flowers, branched cymes or peduncles and smaller rosette size. Note the tips of the leaves on the leaves in the middle of the rosette have a pointed tip due to the margin of the leaf "rolling under" on each side. Once the leaves age, this tends to flatten out and the leaves take on a more rounded or orbicular shape.

The second form of P. minor to show up in cultivation in the US was the form now called "pointed leaf form". This name refers to a characteristic of the younger leaves to roll under at the margins near the apex of the leaf, causing a point to form at the tip. This form is often still exhibited as P. minor without any designation of the variety or form. This form differs from the smooth leaf form in several ways. The rosette tends to stay more compact or smaller in size. The growth rate is slower, for me. The color of the leaves is deeper green and the veining is slightly more prominently incised or "deeper" than with the smooth leaf form. Leaves are not as glossy as on the other two forms. Flowers are smaller, more cupped and have a large white throat. They are bluer in color than the more purple or violet color of the smooth leaf form. Petals are smooth with slight veining, although not as deeply veined as seen in the flowers of the veined leaf form. Lastly, the inflorescences, or peduncles are branched, with primary and secondary bracts. Calyx lobes are longer, there are still six of them, however, being longer, they form a "bell" around the bud, which in this form, tends to hang downward or droop on the inflorescence until just prior to opening.

Judges should note which form they are judging as the different characteristics might be viewed as culture flaws by the inexperienced judge. The pointed leaf form is the smallest of the three forms, is significantly slower to mature for me, and is not as glossy and shiny as the smooth leaf and veined leaf form. Also, in this form, the leaves do not lay as flat on the rosette, causing a more open and upright form to the rosette. These points could easily be attributed to poor or inconsistent culture resulting in a "stressed" plant by a judge, and therefore marked down in the scoring.

A flower of P. minor pointed leaf form.....note that it is smaller, and more cupped, with the calyx extending farther onto the upper lip. The white throat is more pronounced.

A cyme or peduncle from P. minor pointed leaf form. Not that there are primary bracts at the base of the first two branches and secondary bracts at the base of each calyx. The buds hang downward and the calyx lobes are longer forming a cup around the buds. Cymes are rarely ever single flowered, most always they are branched with three to five buds being typical.

Note the secondary bracts at the base of the calyx. This is the only form of P. minor to have this trait.

A close up of the center leaves of the rosette of P. minor pointed leaf form. In the early stages, leaves are more cordate in shape, with a pointed apex, but as they mature, they become more circular or orbicular in shape near the outer rows of the rosette. Leaves show deeply incised veins along the midvein and the lateral veins only.

Sunday, November 1, 2009

Since first coming into cultivation around 1999, the plant labeled P. minor has been a favorite among Pet admirers. The plant appears to have come into cultivation in the US via an independent vendor from China who sold that plant labeled as P. minor. Almost from the very beginning of it's cultivation, though, the plant's identity as P. minor has been in question. To add to the confusion, in the next few years, new forms of the species began to show up in shows. The plants were very similar in many respects, but had distinct differences in both leaf form, growth habit and flowers. I decided to do a series of posts on the forms of this species that I have in cultivation in my collection.

The flower of the plant I grow as P. minor smooth leaf form. The flowers are borne on single flowered cymes...rarely two-flowered.

Lets begin at the beginning. Initially, there was just the one form of P. minor..the one pictured above, in the US. At the time it was introduced, it was called simply, P. minor, as it came labeled from the vendor. The plants were reported to have been collected in China. Leaves on this form were round...orbicular is shape with smooth dorsal (adaxial) leaf surfaces. The plant habit was flat, symmetrical, and the leaves were distinctly glossy in appearance. Flowers are grape-purple, with a white throat and a deep violet purple almost black spot at the very base of the throat, deep inside the corolla. Cymes or peduncles were single flowered, rarely two-flowered. Cymes have three bracts consistently and calyx lobes are six in number..which is odd for a Petrocosmea where all species except P. kerrii have five calyx lobes. (P. kerrii has three calyx lobes).

The three forms of P. minor...smooth leaf form on the top, veined leaf form on the lower left and pointed leaf form on the lower right. All three of these plants are the same age, in a five inch pan pot, and were grown side by side under the same conditions for one year previous to the photo being taken. P. minor smooth leaf form is intermediate between the two in size of the rosette and has the smallest and glossiest leaves. Veining on the leaves of smooth leaf form is very shallow. Leaves cupped in a convex manner.

A cyme and flower bud of P. minor smooth leaf form, showing the six lobed calyx, with the upper three lobes being shorter than the lower three lobes. Cymes are usually single flowered.

Soon after P. minor was introduced, two other forms became evident. One of these, the form now called P. minor veined leaf form, was originally labeled P. sp. '#5' or 'Chinese #5'. I have grown leaves of this form from various sources, all labeled as #5 and Chinese #5 and have found them all identical to P. minor veined leaf form. The veined leaf form is the largest of the three forms in all respects. The leaves are much heavier in substance, with very deep veining along the dorsal (adaxial) surface, giving it a pebbled appearance to the leaves. It's flowers and cymes are also different from the smooth leaf form. The third form is now called pointed leaf form and I have also seen it labeled P. minor holly leaved form. This form has the smallest rosette of the three forms. It grows much more slowly than the other two forms and has branched cymes with smaller flowers. The leaves on this form fold under at the tip and along the margin to give it a pointed appearance. When the leaves of this form are flattened, however, they are also rounded or orbicular in shape. This form has leaves that are a deeper green color than the other two forms and the leaves are not as glossy, although the dorsal (adaxial) surface remains glabrous or smooth (free of hairs).

Flower cymes of the three forms of P. minor....from left to right...smooth leaf form (left), pointed leaf form (center) and veined leaf form (right). The smooth leaf form consistently has three bracts on the cyme, whereas the pointed leaf form also has secondary bracts and a consistently branched cyme.

The flower structure of the P. minors appears to place them within Section -Anisochilus within the genus Petrocosmea. This section has flowers which have shorter upper lobes...roughly one half the length of the lower petal lobes, and the upper lobes fuse to form a hood or upper lip that has two lobes. This characteristic is also present in the flowers of P. sericea and the P. rosettifolia group.

Culture of the three forms of P. minor is consistent with the culture of all other Pets. Since these are some of the largest of all Pet species, they will need larger diameter pots as they mature. I keep them in five inch diameter x two inch deep pan pots (shallow pots) at maturity, although they would easily grow into larger pots if given them. I find these species quite slow to mature, compared to many other species. I allow them to dry out between waterings. They tolerater drying out better than other species, perhaps because the leaves are of a heavy substance and succulent. In hybridization attempts, I found all of the P. minors to be very difficult to work with. They did not accept pollen from each other, by selfing or from other species. They did cooperate as pollen parents in two hybrids, with P. sericea and P. forrestii.

The last thing to note about these species is that all three forms appear to NOT match the description of P. minor in the Flora of China. Differences in the leaf shape (being round or orbicular in shape), size and texture (being glabrous or smooth on the dorsal leaf surface) as well as the six lobed calyx, and the shape of the filaments, cause them not to match any currently described species description within the Flora of China in my opinion. I have studied the flowers, cymes, and leaves under a microscope and carefully compared them to the description within the Flora of China and cannot find a match among the twenty-plus descriptions of Petrocosmea species contained therein.

So, even though these beautiful Petrocosmea species are currently suffering a bit from an identity crisis, they remain among the most unique and beautiful Pets in my collection.

It is always a happy day when a new Petrocosmea seedling flowers for the first time. Usually by that time, I have been able to study to foliar characteristics from the seedlings, but the flowers often show surprisingly high variation in color and characteristics. The latest cross to flower is P. sericea x minor veined leaf form. This is one of only two crosses I was able to get using P. minor and both crosses produced few seeds. In this cross, two plants with similar floral structure were used, and the closer relationship to each other within the genus may have been why this cross succeeded when others have not. Both P. sericea and P. minor exhibit flower structure that appears to place them in Section - Anisochilus, where the upper two petals are often reduced to one half the length of the lower three petals. The two upper petals are fused together into an upper lip or hood with two lobes. This flower form is also seen with the various forms of P. rosettifolia, P. sp. 'China-2005' and P. cavaleriei and P. sp. 'HT-2' and P. sp. 'Yumebutai'. The seedlings all show very uniform foliar characteristics, appearing much like a hairy leaf form of P. minor veined leaf. The cupping of the leaves, seen in P. sericea is only showing up in one seedling, so far. The flowers of the two seedlings which have flowered so far, show some variation between the two parents, with one flower looking more like P. sericea in color and form, showing no white in the throat. The second seedling looks more like the P. minor parent, and showing the white throat of this parent. Both seedlings show the promise of becoming quite large plants, and I will be potting them on into larger pans soon to allow them to develope more. One characteristic that I am not liking in these seedlings is that they both have very long, wiry peduncles. I'll evaluate that in the next flowering with more maturity. If the plants do indeed grow into large rosettes, the longer peduncles may be necessary for the flowers to extend beyond the long petioles of the leaves in the rosette, so I am not too concerned yet. They peduncles do both show a nice wine-purple coloring.

The first seedling to flower from the cross of P. sericea x minor veined leaf form resembles P. sericea in flower form and color.

The second seedling to flower resembles P. minor veined leaf in flower form and color.

All of the seedlings have been quite uniform in foliage form, looking like a fuzzy leafed form of P. minor veined leaf form as can be seen in this seedling above.

The flower of Petrocosmea sericea - very similar in form to P. minor flowers. The two species are likely very closely related to each other. The two upper petals are fused into a two-lobed lip or "hood" to the flowers. Upper petal length is roughly one half the length of the lower three petals, and likely places these species in Section - Anisochilus, along with the plants labeled P. rosettifolia, whose flowers are very similar in shape.

The flower of Petrocosmea minor veined leaf form also share the flower form and structure of Section- Anisochilus with P. sericea..the other parent in this cross. In this form of P. minor, the leaves are deeply veined. This form also shows the veining in the lower petals of the flowers, which the other forms of P. minor do not have. The flowers of this form are a bit smaller and have a more pronounced clear white throat.